I'm going to unquestionably learn well the first two (MSA mainly for writing though). I'd be happy with a lot of Persian/Canto but not perfect, an Arabic dialect is crucial to speak with people, Old Spanish and French are out of pure geekiness, I imagine myself speaking Hindi but it's not a journey I want to start for now. For the rest (Port./Latin/Nahuatl/Russian/Gujarati) it all depends on how things turn out (say, if I become a close friend of a Russian/Gujarati speaker or something I'd be more than delighted to learn it).

Mine:GermanNorwegianLuxembourgishJapaneseCornishDutchThose are the ones I'll most likely learn fluently, but I haven't fully committed to Luxembourgish yet.

Possibly, in order of possibility:ManxLatinQuite possibly some Old Norse, it's pretty sexyMaybe Persian, it's pretty coolI also want to maybe learn either Latvian or Lithuanian, I can't decide which, and surely not both, and also a Finno-Ugric language, in this order: Võro, Estonian, Finnish/Hungarian, not sure which order they should go in, since there's an equal chance for both. In reality, I doubt learning Võro is possible, because I don't think many (if any at all) resources are in English, and I have no idea about other resources for it in any other language.

Less possibly:MandarinArabicLow possibility: Some Native American language, like Cherokee or Lakota.

Well since my area of interest includes mostly history of East Central Europe I plan to learn languages of this region, even those I'm not particularly interested in. Just in case I change my signature these language would be:Hungarian, German, Polish, Sorbian, Romanian, Slovenian, Lithuanian, Latvian, Albanian, Romany, and I'll try to improve my knowledge of Czech, Ruthenian, Macedonian, Bulgarian, Ukrainian, Belarusian and Russian.

I would also like to know languages that were used in these regions in the past: Latin, Koine Greek, Gothic, Old High German, Old Hungarian, Ottoman Turkish, Old Prussian, and improve my knowledge of Old Church Slavonic and Church Slavonic.

But I also would like to learn languages of other cultures I'm interested in: Old Irish, Old French, Old English, Old Norse, Classical Greek, Ancient Egyptian, Coptic, Hittite, Sanskrit.

There are couple of modern languages I would like to learn also, for instance French, Italian, Spanish, Finnish and Swedish, the former three because there is a large volume of literature available on the subject of palaeolinguistics and history, the latter two because I just like them.

I have my whole life ahead of me and I plan to live a very long one, and I'll spend most of it studying I guess. I can't tell how many of these languages I'll learn or even try to learn, but most of them require only passive understanding, and as I don't plan to really make anything of them except get to the knowledge I seek it is possible.